William George Killian
- Bats Left, Throws Right
- Height 6' 0", Weight 190-210 lb.
- High School Chippewa Hills High School
Catcher Billy Killian was selected by the San Diego Padres in the third round of the 2004 amateur draft. He was signed by scout Jeff Stewart and made his pro debut that summer with the AZL Padres, hitting .230 with 13 RBI in 40 games before earning a promotion to the AAA Portland Beavers at the end of August and going 1-for-7 in 3 games. After splitting 2005 between three clubs, he was traded to the Texas Rangers organization prior to the 2006 campaign. On August 2, 2007, he was sent to the Chicago White Sox. He moved on to the Baltimore Orioles organization in 2009, spending the year with the Frederick Keys.